FIELD OF THE INVENTION
This invention is directed to organic compounds and is particularly concerned with a novel process for the preparation of 6-phenyl-4H-s-triazolo[4,3-a][1,4]benzodiazepines and the intermediates thereof.
The novel process or production can be illustratively represented as follows: ##SPC1##
Wherein A is selected from the group consisting of ##SPC2##
And ##EQU1## wherein R.sub.1 is selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, inclusive, phenyl, benzyl, and COOR' wherein R' is alkyl defined as above; and wherein R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are selected from the group consisting of hydrogen, alkyl of 1 to 3 carbon atoms, inclusive, halogen, nitro, cyano, trifluoromethyl, and alkoxy, alkylthio, alkylsulfinyl, alkylsulfonyl, and alkanoylamino, in which the carbon chain moieties are of 1 to 3 carbon atoms, inclusive, and dialkylamino in which alkyl is defined as above.
The intermediates corresponding to formula II are specifically claimed.
The process of this invention comprises: treating a 2-[3-(hydroxymethyl)-4H-1,2,4-triazol-4-yl] benzophenone (I) with either methanesulfonyl chloride in the presence of a base (e.g. triethylamine, or other volatile tertiary amine) at -40.degree. to +10.degree. C. to obtain the compound II wherein ##EQU2## or treating I with phthalimide and triphenylphosphine in the presence of a hydrogen acceptor e.g. diethyl azodicarboxylate to give the compound II wherein A is ##SPC3##
The compound of formula II ##EQU3## is then treated with gaseous ammonia, preferably in the presence of an alkali iodide, between 10.degree. to 50.degree. C. to give the compound III.
The compound of formula II wherein A is ##SPC4##
Is treated with hydrazine hydrate in a lower alkanol (1 to 3 carbon atoms) for one to five hours at 25.degree.-100.degree. to give the corresponding compound of formula III above.